Upload
hunter
View
82
Download
2
Embed Size (px)
DESCRIPTION
Gas-Lift Optimization and Diagnosis by using Wellflo and Dynalift Simulators By Jayant Sadare & Dr. Faleh T. Al-Saadoon Texas A&M University-Kingsville ASME/API/ISO GAS-LIFT WORKSHOP-2004. Objectives. Optimization (Wellflo) - PowerPoint PPT Presentation
Citation preview
Gas-Lift Optimization and Diagnosis by using Wellflo and Dynalift Simulators
By
Jayant Sadare &
Dr. Faleh T. Al-Saadoon
Texas A&M University-Kingsville
ASME/API/ISO GAS-LIFT WORKSHOP-2004
Objectives
Optimization (Wellflo) (Wellflo)
Advanced Gas Valve ModelingAdvanced Gas Valve Modeling
Diagnosis and Verification (Dynalift)Diagnosis and Verification (Dynalift)
ImplementationImplementation
Wellflo Simulator (EPS)Wellflo Simulator (EPS)
USES Nodal Analysis for
Designing
Modeling
Optimizing
Troubleshooting
Input Data Summary Fluid Properties
- Oil Gravity = 35 deg. API
- Water Gravity = 1.03
- Gas Gravity = 0.70
- Produced Gas-Oil Ratio = 50.00 scf/STB
- Percent Water (%) = 45
Well-bore Data
- Production Casing: 7.000 inch OD × 6.094-inch ID set @ 7100 ft (TVD)
- Tubing : 2.875- inch OD × 2.441-inch ID set @6950 ft (TVD)
- Well Injection Angle (with vertical) = 0
Contd…..
Reservoir Data
Reservoir shut-in pressure = 2400 psig @ 7000 ft
Reservoir Temperature = 206 deg F
Productivity Index (Straight line) = 2.00 STB/day/psi
Gas-Lift Data
Casing Head Pressure = 1450 psig
Operating valve Differential Pressure = 150.00 psi
Well-head pressure = 102.5 psig
Minimum Valve Spacing = 350 ft
Injection Gas Rate = 1.000 MMscf/day
Why Artificial lift??
Continuous Gas Lift design - Point of Injection
• Specify:
- Casing head pressure
- GLR or Qgi
- Pressure drop across valve
• Calculates maximum depth of injection and well performance for gas lift
• Sensitivity to CHP, Qgi, GLR
Inflow / Outflow Performance Curve
Performance Analysis Curve
Pressure and Temperature Vs Depth Analysis
Gas Lift Design - valve spacing for continuousgas lift installations
Specify
- Casing head pressure - GLR or Qgi- Pressure drop across valve - Kill fluid gradient - Maximum depth - Target operating rate
- Design Margins
Calculates
- depth of unloading and operating valves (IPO/PPO) - Corresponding tubing/casing pressures & temperatures
Gas-Lift Valve Spacing
Advanced Gas Valve Modeling (AGVM)
• True performance of commercial gas lift valves
• True operating point of system
• Sensitivity to valve type, port size, valve settings and gas injection parameters
• Gas-charged and orifice valve performance
True Valve Performance Curve
Valve Performance Curve For Orifice Valve
Curve Showing Closed Unloading Valve No. 1
Dynalift Simulator (EPS)
Dynamic (Unsteady-State) simulation tool for
Verification
Troubleshooting
Learning
Dynamic Gas-Lift Simulation
This Dynamic simulator uses all the equations used by a steady-state simulator except it adds the dynamic variable (Time).
Uses real correlations to simulate the behavior of gas-lift valves under bottom-hole dynamic conditions.
By controlling the injection conditions, the production parameters are observed to define if the design will work with the selected gas-lift valves.
More realistic performance can be generated
Simulates the system by considering the casing head pressure, gas-injection rate and wellhead pressure at the same time.
Contd……
This Dynamic simulator is an excellent tool for
identifying operational problems with gas-lift
installations.
Also best tool to understand the causes for
unstable production conditions which not
understood with a steady state simulator
It is the best tool for gas lift valves to verify
its performance from the unloading operation
through all the production life.
Working Screen for Dynamic Simulator
Valve Data Screen
Comparison of Dynamic & Steady-state Performance Curve
Conclusion
Combination of Wellflo and Dynalift is one of the best tool for students to understand gas-lift simulation.
Advanced Gas Valve Modeling (AGVM) is the heartof steady-state simulation.
Do we really need Dynamic Simulation?
- Accurately model the well unloading for better design and diagnosis- Minimize unloading time - Accurate valve performance curves- Improve operational procedures
Thank you